﻿*{
	margin:0;
	padding:0;
	}
body{
	margin:10px;
	}
	
#header{
	border:1px solid black;
	width:600px;
	height:60px;
	margin:0 auto;
	text-align:center;
	line-height:60px;
	}
 #header h1{
	font-size:16px;
	}
	
#body{
	border:1px solid black;
	width:600px;
	margin:0 auto;
	position:relative;  
	/*使用BODY的相对定位，设置BODY的左上角为基准0坐标，
	在此基础上调其他元素的绝对定位坐标。*/
	 
	}
 #nav{
 	width:100px;
 	height:300px;
 	background:orange;
 	margin-bottom:10px;
 	}
 #nav2{
 	width:100px;
 	height:300px;
 	background:yellow;
 	margin-bottom:10px;
 	position:absolute;
 	top:0px;
 	left:100px;
 	}
 	#main{
 	width:400px;
 	height:300px;
 	background:red;
 	margin-bottom:10px;
 	position:absolute;
 	top:0px;
 	left:200px;
 	 
 	}
	
	
#footer{
	border:1px solid black;
	width:600px;
	height:30px;
	margin:0 auto;
	text-align:center;
	line-height:30px;
	}